This invention relates to a computer system including storage systems, host computers, and a management computer, and more particularly to a technology for restoring backup data.
The computer system which includes the host computers and the storage systems should prevent data loss even when an unexpected accident, disaster, or the like occurs. For that purpose, data in the storage system provided for the computer system are stored in (backed up to) tapes or other storage systems. When a failure occurs, the computer system uses the backup data to recover (restore) data.
It is necessary for the computer system to restore the data with an RTO (Recovery Time Objective) and an RPO (Recovery Point Objective) being reduced.
The RTO refers to a time required for a recovery processing of the computer system. Specifically, the RTO is a difference in time between a time point when the computer system stops and a time point when the computer system is recovered. The RPO is a value indicating freshness of data used to recover the computer system. Specifically, the RPO is a difference in time between a time point when the computer system stops and a check point (CP) to which the computer system is recovered.
JP 2005-18738 A discloses a computer system which is capable of performing restore operation with the reduced RPO and RTO. According to this computer system, a storage system stores journal data each time data to which a host computer has issued a write request is stored in a volume. Then, in the computer system, the journal data stored in the storage system is used to restore the data. According to this configuration, even when an application executed by the host computer does not store journal data, data can be restored in the computer system.